System comprising a multilevel warehouse racking system comprising tote transfer zones, materials handling vehicles, and transporters, and methods of use thereof

ABSTRACT

Goods storage and retrieval systems and materials handling vehicles are provided. The goods storage and retrieval system includes a multilevel warehouse racking system; a materials handling vehicle comprising a mast assembly, a picking attachment, and vehicle-based cart engagement hardware; a mobile storage cart; and a transporter comprising transporter-based engagement hardware. The transporter-based engagement hardware enables the transporter to engage, transport, and disengage the mobile storage cart. The vehicle-based cart engagement hardware is coupled to the mast assembly to (i) engage and disengage the mobile storage cart and (ii) transport the mobile storage cart to multiple levels of the multilevel warehouse racking system. The mast assembly and the picking attachment are configured to access multiple levels of the multilevel warehouse racking system. The picking attachment is configured to transfer totes between the multilevel warehouse racking system and the mobile storage cart.

BACKGROUND

The present disclosure relates to a goods storage and retrieval systemin a warehouse environment. The system functionally integrates amultilevel warehouse racking system, one or more materials handlingvehicles, one or more mobile storage carts, and one or moretransporters. For the purposes of defining and describing the conceptsand scope of the present disclosure, it is noted that a “warehouse”encompasses any indoor or outdoor industrial facility in which materialshandling vehicles transport goods including, but not limited to, indooror outdoor industrial facilities that are intended primarily for thestorage of goods, such as those where multi-level racks are arranged inaisles, and manufacturing facilities where goods are transported aboutthe facility by materials handling vehicles for use in one or moremanufacturing processes.

BRIEF SUMMARY

According to the subject matter of the present disclosure, goods-to-manwarehousing systems are provided to increase the adaptability, utility,and efficiency of partially and fully autonomous materials handlingvehicles and transporters in the warehouse environment.

In accordance with one embodiment of the present disclosure, a goodsstorage and retrieval system is provided. The goods storage andretrieval system comprises a multilevel warehouse racking systemcomprising a tote transfer zone, a materials handling vehicle comprisinga mast assembly and a picking attachment, a target tote, and atransporter comprising transporter-based engagement hardware. Thetransporter-based engagement hardware enables the transporter to engage,transport, and disengage the target tote at the tote transfer zoneindependent of movement of the materials handling vehicle within thegoods storage and retrieval system. The picking attachment is coupled tothe mast assembly for movement along a lifting dimension of the mastassembly to (i) engage and disengage the target tote at the totetransfer zone and at multiple levels of the multilevel warehouse rackingsystem independent of movement of the transporter within the goodsstorage and retrieval system and (ii) transport the target tote tomultiple levels of the multilevel warehouse racking system independentof movement of the transporter within the goods storage and retrievalsystem. The mast assembly and the picking attachment are configured toaccess multiple levels of the multilevel warehouse racking system.

In accordance with another embodiment of the present disclosure, amethod of operating a goods storage and retrieval system is provided.The method comprises providing the goods storage and retrieval systemcomprising a multilevel warehouse racking system, a materials handlingvehicle disposed on an inventory transit surface, a tote transfer zone,a target tote, and a transporter comprising transporter-based engagementhardware. The materials handling vehicle comprises a traction controlunit, a braking system, and a steering assembly, each operativelycoupled to one or more of the vehicle wheels. The materials handlingvehicle further comprises a mast assembly, a fork carriage assemblymovably coupled to the mast assembly, a mast assembly control unit, acarriage control unit, a picking attachment comprising an X-Y-Z-Ψpositioner secured to the fork carriage assembly, a navigationsubsystem, and one or more vehicular controllers in communication withthe traction control unit, the braking system, the steering assembly,the mast assembly control unit, the carriage control unit, the pickingattachment, and the navigation subsystem. The method comprisesnavigating the materials handling vehicle along the inventory transitsurface to the target tote through use of the navigation subsystem andthe one or more vehicular controllers independent of movement of thetransporter within the goods storage and retrieval system. The methodcomprises engaging or disengaging the target tote with the pickingattachment secured to the fork carriage assembly through use of theX-Y-Z-Ψ positioner at the tote transfer zone and at multiple levels ofthe multilevel warehouse racking system independent of movement of thetransporter within the goods storage and retrieval system. The methodfurther comprises placing with the picking attachment the target tote onthe tote transfer zone or on a level of the multilevel warehouse rackingsystem and engaging the target tote with the transporter through use ofthe transporter-based engagement hardware comprising a transporterlifting surface.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

The following detailed description of specific embodiments of thepresent disclosure can be best understood when read in conjunction withthe following drawings, where like structure is indicated with likereference numerals and in which:

FIG. 1A illustrates a goods selection terminal including an operatorplatform, a goods access portal, an operator, a transporter, and atarget tote according to various embodiments shown and described herein;

FIG. 1B illustrates a goods selection terminal including an operatorplatform, a goods access portal, an operator, a transporter, and atarget tote according to various embodiments shown and described herein;

FIG. 1C illustrates a mobile storage cart and a transporter according tovarious embodiments shown and described herein;

FIG. 1D illustrates a mobile storage cart and a transporter according tovarious embodiments shown and described herein;

FIG. 1E illustrates a tote transfer zone, a plurality of totes, and atransporter according to various embodiments shown and described herein;

FIG. 1F illustrates a tote transfer zone, a plurality of totes, and atransporter according to various embodiments shown and described herein;

FIG. 1G illustrates a tote transfer zone, a tote, and a transporteraccording to various embodiments shown and described herein;

FIG. 1H illustrates a tote transfer zone, a tote, and a transporteraccording to various embodiments shown and described herein;

FIG. 1I illustrates a goods storage and retrieval system including amultilevel warehouse racking system, a plurality of materials handlingvehicles, a plurality of totes, a plurality of transporters, and aplurality of mobile storage carts according to various embodiments shownand described herein;

FIG. 2 illustrates a materials handling vehicle engaging a mobilestorage cart according to various embodiments shown and describedherein;

FIG. 3 illustrates a materials handling vehicle engaging a mobilestorage cart according to various embodiments shown and describedherein;

FIG. 4 illustrates a materials handling vehicle engaging a mobilestorage cart according to various embodiments shown and describedherein;

FIG. 5 illustrates a materials handling vehicle including, inter alia, adrive unit case housing a removable hand-held drive unit, a mobilestorage cart with an anti-rock cart engagement mechanism and mobilestorage cart support platform, and a picking attachment in position toengage a target tote according to various embodiments shown anddescribed herein;

FIG. 5A is a schematic illustration of a goods storage and retrievalsystem including a multilevel warehouse racking system, a plurality ofmaterials handling vehicles, and a plurality of mobile storage cartsaccording to various embodiments shown and described herein;

FIG. 5B illustrates a unitary materials handling platform having cartengagement sensors according to various embodiments shown and describedherein;

FIG. 5C illustrates a materials handling vehicle having cart engagementsensors according to various embodiments shown and described herein;

FIG. 6 illustrates the picking attachment of FIG. 5 according to variousembodiments shown and described herein;

FIG. 7 illustrates the picking attachment and the materials handlingvehicle of FIG. 5 in a position in which a slide-out of the pickingattachment are in an extended position to either retrieve the targettote from, or store the target tote on, a rack module according tovarious embodiments shown and described herein;

FIG. 7A illustrates a target tote according to various embodiments shownand described herein;

FIG. 7B illustrates a tote transfer zone and a plurality of target totesaccording to various embodiments shown and described herein;

FIG. 8 illustrates the picking attachment and the materials handlingvehicle of FIG. 5 in a position in which the slide-out of the pickingattachment has positioned the target tote in the picking attachment in asecured position according to various embodiments shown and describedherein;

FIG. 9 illustrates the picking attachment and the materials handlingvehicle of FIG. 5 in a position in which the picking attachment is inrotational alignment with a shelf of the engaged mobile storage cart andthe slide-out is in an extended position to either retrieve the targettote from or store the target tote on the shelf according to variousembodiments shown and described herein;

FIG. 10 illustrates a front view of the mobile storage cart according tovarious embodiments shown and described herein;

FIG. 11 illustrates a materials handling vehicle with a monoforkcarriage assembly according to various embodiments shown and describedherein;

FIG. 12 is a schematic illustration of various vehicular controllers ofthe materials handling vehicle in communication with a hand-held driveunit and vehicle subsystems according to various embodiments shown anddescribed herein;

FIG. 13 illustrates the drive unit case of FIG. 5 in an open position toshow the removable hand-held drive unit according to various embodimentsshown and described herein;

FIG. 14 is a schematic illustration of a computing device according tovarious embodiments shown and described herein;

FIG. 15 is a flow chart illustrating cart acquisition methodologyaccording to various embodiments shown and described herein; and

FIG. 16 is a flow chart illustrating tote engagement methodologyaccording to various embodiments shown and described herein.

DETAILED DESCRIPTION

Referring initially to FIG. 1I, a goods storage and retrieval system 100comprises a multilevel warehouse racking system 200, a materialshandling vehicle 300, a mobile storage cart 400, and a transporter 500,disposed on an inventory transit surface 110. The materials handlingvehicle 300 comprises vehicle-based cart engagement hardware 316 (FIG.5), a mast assembly 302, and a picking attachment 320 (FIG. 5). Themultilevel warehouse racking system 200 comprises a tote transfer zone219. As shown in FIGS. 1C and 1D, the transporter 500 comprisestransporter-based engagement hardware 540 that enables the transporter500 to engage, transport, and disengage the mobile storage cart 400 byraising a lifting surface 520 of the transporter 500 to contact themobile storage cart 400. Referring back to FIG. 1I, the transporter 500may engage, transport, and disengage the mobile storage cart 400 at avariety of locations along an inventory transit surface 110 of the goodsstorage and retrieval system 100 independent of movement of thematerials handling vehicle 300 within the goods storage and retrievalsystem 100. Referring to FIGS. 1I, 1E, and 1F, the transporter-basedengagement hardware 540 further enables the transporter 500 to engage,transport, and disengage a target tote 214 at the tote transfer zone 219by raising a lifting surface 520 of the transporter 500 to contact thetarget tote 214 independent of movement of the materials handlingvehicle 300 within the goods storage and retrieval system 100.

Referring to FIGS. 1I and 5, the vehicle-based cart engagement hardware316 is coupled to the mast assembly 302 for movement along a liftingdimension (along the Z′-axis as shown in FIG. 1I) of the mast assembly302 to (i) engage and disengage the mobile storage cart 400 at a varietyof locations along the inventory transit surface 110 independent ofmovement of the transporter 500 within the goods storage and retrievalsystem 100 and (ii) transport the mobile storage cart 400 to multiplelevels of the multilevel warehouse racking system 200 independent ofmovement of the transporter 500 within the goods storage and retrievalsystem 100. The picking attachment 320 is coupled to the mast assembly302 for movement along a lifting dimension of the mast assembly 302 to(i) engage and disengage the target tote at the tote transfer zone 219,the mobile storage cart 400, and at multiple, vertically spaced, levelsof the multilevel warehouse racking system 200 independent of movementof the transporter 500 within the goods storage and retrieval system 100and (ii) transport the target tote to the tote transfer zone 219, themobile storage cart 400, and to multiple levels of the multilevelwarehouse racking system 200 independent of movement of the transporter500 within the goods storage and retrieval system 100.

The mast assembly 302 and the picking attachment 320 are configured toaccess multiple levels of the multilevel warehouse racking system 200.The picking attachment 320 of the materials handling vehicle 300 isconfigured to transfer totes between the multilevel warehouse rackingsystem 200 and the mobile storage cart 400 at multiple levels of themultilevel warehouse racking system 200 when the mobile storage cart 400is engaged by the materials handling vehicle 300. Additionally oralternatively, the picking attachment 320 of the materials handlingvehicle 300 may be configured to transfer totes between multiple levelsof the multilevel warehouse racking system 200 and the transporter 500.Additionally or alternatively, the picking attachment 320 of thematerials handling vehicle 300 may be configured to transfer totesbetween the transporter 500 and the mobile storage cart 400 when themobile storage cart 400 is engaged by the materials handling vehicle300. As described in more detail below, the goods storage and retrievalsystem 100 may further comprise a cart home position 410, one or moremobile storage cart transfer nodes 420, one or more goods receivingstations 610, and one or more warehouse management computing hubs.

Referring still to FIGS. 1I and 5, the materials handling vehicle 300may further comprise a vehicle body 301, a plurality of wheels 306supporting the vehicle body 301, a traction control unit 372, a brakingsystem 371, and a steering assembly 373, each operatively coupled to oneor more of the vehicle wheels 306. The materials handling vehicle 300may further comprise a mast assembly 302, a fork carriage assembly 310movably coupled to the mast assembly 302, a mast assembly control unit374, a carriage control unit 375, the picking attachment 320 secured tothe fork carriage assembly 310, a cart engagement subsystem 350, and anavigation subsystem 360.

Referring to FIGS. 5 and 12, the materials handling vehicle 300 maycomprise one or more vehicular controllers in communication with thetraction control unit 372, the braking system 371, the steering assembly373, the mast assembly control unit 374, the carriage control unit 375,the picking attachment 320, the cart engagement subsystem 350, and thenavigation subsystem 360. The vehicular controller(s) may comprise apicking controller 376, a braking controller 377, a traction controller378, a steering controller 379, a mast controller 380, or one or moreintegrated controllers, to control operational functions of the pickingattachment 320, the braking system 371, traction control unit 372, thesteering assembly 373, or the mast assembly control unit 374. Thevehicular controller(s) will be described in further detail later in theapplication.

While the mast assembly 302 is depicted in FIG. 1I as extending to theheight of the racks 210, it is understood and within the scope of thisdisclosure that the mast assembly 302 may extend to different heightswith respect to the racks 210. For example, the mast assembly 302 may bea multi-stage mast, with or without a free-lift feature. Theaforementioned materials handling vehicles may include lift trucksavailable from Crown Equipment Corporation such as, for example, SPSeries Order Pickers such as the Crown SP 3500/4500 Series Order Pickeror TSP Series Order Pickers such as the Crown TSP 6500/7000 Series OrderPicker.

Referring now to FIG. 5, the vehicle body 301 of the materials handlingvehicle 300 may be described as comprising a fork side 303 and a powerunit side 304, with the fork carriage assembly 310 positioned at thefork side 303 of the vehicle body 301 and being movably coupled to themast assembly 302. The materials handling vehicle 300 may also comprisean operator compartment 307 that may also be movably coupled to the mastassembly 302. This operator compartment 307 may be positioned betweenthe fork carriage assembly 310 and the power unit side 304 of thevehicle body 301. In embodiments, the materials handling vehicle 300does not include the operator compartment 307.

Referring again to FIG. 1I, a variety of technologies may be provided tofacilitate partial or fully autonomous navigation of the materialshandling vehicle 300, including conventional, or yet-to-be developedtechnology. For example, and not by way of limitation, radio frequencyidentification (RFID) tags may be embedded in the inventory transitsurface 110, or secured to various warehouse objects, to help facilitatepartially or fully autonomous navigation. Wire guidance systems, whichare well documented in the art, may also be employed to help facilitatepartially or fully autonomous navigation. In one contemplatedembodiment, RFID tags embedded in the inventory transit surface 110 maybe used in conjunction with a wire guidance system. In which case, itmay be advantageous to embed the RFID tags 230 at vehicle stoplocations, pick-place locations, tote transfer zones, transfer nodelocations, or other significant navigational markers along a rackingsystem aisle, as shown in FIG. 1I. Partially or fully autonomousnavigation may also be implemented, by way of non-limiting examples,through laser-based navigation, time of flight cameras, environmentalbased location, overhead feature-based localization,illumination-invariant feature detection, map partitioning,pre-positioned object-based localization, and/or transversal edgedetection based localization. The vehicle stop locations may be recordedin a navigation map in the navigation subsystem 360 (FIG. 12) of thematerials handling vehicle 300 such that physical RFID tags 230 are notneeded for the materials handling vehicle 300 to position itselfcorrectly at a vehicle stop location.

Referring to FIG. 1I, the mobile storage carts 400 may be presented as amultilevel storage cart 400 with individual container bays 430 that areconfigured to accommodate at least one tote 213 which can carry aplurality of different types of goods. In this embodiment, the mobilestorage carts 400 are structurally configured to stand on an inventorytransit surface 110 while permitting transporter travel there beneath.Specifically, the mobile storage cart 400 comprises a transporter accessopening 510 that is sized and configured to permit the transporter 500to enter and exit through one or more of a plurality of transporteraccess openings 510 along the inventory transit surface 110.Furthermore, the mobile storage cart 400 comprises at least twovertically-oriented fork slots 450 (shown in FIG. 5).

Referring to FIGS. 1A-1G and 1I, the transporter 500 comprisestransporter-based engagement hardware 540 that enables the transporter500 to transport mobile storage carts 400 from one or more mobilestorage cart transfer nodes 420 to one or more goods receiving stations610 of the goods-to-man warehousing system 600. For example, thetransporter 500 may feature a lifting surface 520 (shown in FIG. 1A) andbe structurally configured to lift a mobile storage cart 400 off of theinventory transit surface 110 upon which the mobile storage cart 400 issupported by elevating the transporter lifting surface from a travelingheight (as shown in FIGS. 1B and 1G) to a cart contacting height (asshown in FIG. 1C) and then to a transporting height (as shown in FIGS.1D and 1F). Referring back to FIG. 1I, each of the mobile storage carts400 may be structurally configured to permit the transporter 500 toenter and exit a lifting zone 530 beneath the mobile storage cart 400 inat least two orthogonal directions, with the lifting surface of thetransporter 500 at the traveling height.

Similarly, the transporter 500 may feature a lifting surface 520 and bestructurally configured to lift the target tote 214, as shown in FIGS.1E-1F. Referring to FIGS. 1I, 1E-1G, 7A, and 7B, the target tote 214 hasa tote width of t and comprises a pair of protruding rims 214Apositioned on opposite sides of the target tote 214. These protrudingrims 214A define a target tote rimmed width r. Totes may be a variety ofdifferent sizes, varying from smaller than the lifting surface 520 ofthe transporter 500 to larger than the lifting surface 520 of thetransporter 500. In some embodiments, the bottom of the tote 214 may beapproximately the same size as the lifting surface 520 of thetransporter 500. In some embodiments, the length and width of the tote214 may be approximately equal. In other embodiments, the length of thetote 214 may be greater than the width of the tote 214. In embodiments,the width and height of the tote 214 may be approximately equal. Inother embodiments, the height of the tote 214 may be less than the widthof the tote 214. In other embodiments, the height of the tote 214 may begreater than the width of the tote 214. The tote transfer zone 219comprises a plurality of tote suspension tracks 219A defined by a trackspacing b. For the totes 214 to rest securely on tote suspension tracks219A of the tote transfer zone 219, t<b<r. The tote transfer zone 219 iselevated above an inventory transit surface 110 of the goods storage andretrieval system 100 such that the totes 214 stored therein areaccessible by the transporter 500. The tote transfer zone 219 may form abottom level of the multilevel warehouse racking system 200. In someembodiments, as shown in FIG. 1H, the multilevel warehouse rackingsystem 200 comprises a first rack and a second rack arranged on oppositesides of a racking system aisle. The first and second racks define endpoints of the racking system aisle and the tote transfer zone 219extends past the end points of the racking system aisle. In analternative embodiment, the tote transfer zone 219 does not extend pastthe end points of the racking system aisle and is instead inset withinthe rack of the multilevel warehouse racking system 200. When the totetransfer zone 219 is inset within the rack 210 of the multilevelwarehouse racking system 200, the tote transfer zone 219 may form abottom level of the multilevel warehouse racking system 200.

In embodiments, the transporter 500 may be structurally configured suchthat the lifting surface 520 lifts the target tote 214 relative to atote supporting surface (in some embodiments, this may include the totesuspension tracks 219A) of the tote transfer zone 219. The liftingsurface 520 of the transporter 500 may lift the target tote 214 byelevating the transporter lifting surface 520 from the traveling heightto a rack height (shown in FIG. 1E) and then to the transporting height(shown in FIG. 1F). The lifting surface 520 of the transporter 500 maybe structurally configured to lower the target tote 214 onto a totesupporting surface (such as the tote suspension tracks 219A) of the totetransfer zone 219 by lowering the transporter lifting surface 520 fromthe transporting height (shown in FIG. 1F) to the rack height (shown inFIG. 1E), such that the protruding rims 214A of the target tote 214 reston the tote suspension tracks 219A.

The multilevel warehouse racking system 200 may comprise a plurality ofracking system aisles 220 between the racks 210. FIG. 1I illustrates anembodiment of a rack 210 of the multilevel warehouse racking system 200having a plurality of shelves 240 having at least a portion configuredto support a rack module 211 configured to store one or more totes 213.In embodiments, the rack module 211 may be similar to or the same as therack modules disclosed in U.S. Patent Application Publication2017/0334644. The transporter 500 may be further configured to transportthe mobile storage cart 400 within, into, and out of the racking systemaisles 220. Further, the mobile storage carts 400 may be structurallyconfigured for a transporter 500 to travel there beneath by, forexample, ensuring that a bottom surface of a lowest storage level ofeach of the mobile storage carts 400 has a height exceeding thetraveling height of the transporter lifting surface of the transporter500. As shown in FIGS. 1C and 1D, the lifting surface 520 of thetransporter 500 may lift the mobile storage cart 400 by elevating thetransporter lifting surface 520 from the traveling height to anengagement height (shown in FIG. 1C) and then to the transporting height(shown in FIG. 1D). Referring again to FIG. 1I, in embodiments, thetravel path 130 beneath the multilevel warehouse racking system 200 forthe transporter 500 is a travel path extending along the inventorytransit surface 110, in a storage plane defined by the distributed arrayof racks 210, which follow the shape of the distributed array of racks210.

Referring now to FIGS. 5, 6, and 12, as stated previously, the materialshandling vehicle 300 further includes a picking attachment 320. Thepicking attachment 320 may be added as a vehicle retrofit such that thepicking attachment 320 and materials handling vehicle 300 collectivelydefine dual axis vertical displacement. More specifically, as anon-limiting example, the mast assembly 302 and the mast assemblycontrol unit 374 may be configured to move the fork carriage assembly310 along a vertical axis Z′, and the picking attachment 320, whichcomprises the X-Y-Z-Ψ positioner 322, may be secured to the forkcarriage assembly 310. The vehicular controller(s) of the materialshandling vehicle 300 executes vehicle functions to use the X-Y-Z-Ψpositioner 322 of the picking attachment 320 to engage and disengage atarget tote 214 positioned in the multilevel warehouse racking system200 with the picking attachment 320. The mast assembly 302, mastassembly control unit 374, and the picking attachment 320 arecollectively configured such that movement of the X-Y-Z-Ψ positioner 322along the Z-axis 328 by the picking attachment 320 is independent ofmovement of the fork carriage assembly 310 along the vertical axis Z′ bythe mast assembly 302 and mast assembly control unit 374. It is notedthat “independent” movement means that the X-Y-Z-Ψ positioner 322 caneffectuate vertical displacement without relying on movement of the forkcarriage assembly 310 along the vertical axis Z′.

In embodiments, the mast assembly 302, mast assembly control unit 374,and the picking attachment 320 are collectively configured such thatmovement of the X-Y-Z-Ψ positioner 322 along the Z-axis 328 by thepicking attachment 320 is supplemented by movement of the fork carriageassembly 310 along the vertical axis Z′ by the mast assembly 302 andmast assembly control unit 374. “Supplemental” movement contemplatesthat, since the picking attachment 320 is secured to the fork carriageassembly 310, movement of the X-Y-Z-Ψ positioner 322 along the Z-axis328 by the picking attachment 320 can also result from movement of thefork carriage assembly 310 (for example, with respect to the mastassembly 302) along the vertical axis Z′.

Referring to FIGS. 6-9, the X-Y-Z-Ψ positioner 322 may comprise aslide-out 334 that is configured to extend and retract to engage thetarget tote 214. The slide-out 334, which may be a telescoping assembly,is provided with hardware that selectively engages the target tote 214to push and pull the target tote 214 into, and out of, a warehouse shelf240 (shown in FIG. 1I), a container bay 430 of the mobile storage cart400 (shown in FIG. 1I), or the transporter lifting surface 520 (shown inFIG. 1E), in a sliding motion. The slide-out 334 may be configured toslide within slots 336 defined in a pair of inner side walls 338 of thepicking attachment 320. In embodiments, the slide-out 334 may includeslide rails, ball bearing extension slides, or both. In embodiments, andnot by way of limitation, the hardware that selectively engages thetarget tote 214 may be pivoting engagement fingers that pivot into andout of a sliding path of a target tote 214 for tote engagement. Inembodiments, and not by way of limitation, the hardware that selectivelyengages the target tote 214 may be a mechanism configured to grip thetarget tote 214 such as, for example, at least one of a claw, a gripper,one or more vacuum cups, electromagnetic coils, an articulating arm, andthe like.

Referring to FIG. 5, as stated previously, the materials handlingvehicle 300 includes vehicle-based cart engagement hardware 316. Thevehicle-based cart engagement hardware 316 may comprise a mobile storagecart support platform 312 defined by one or more vertically-orientedcart lifting forks 314, in which the major faces of the respective cartlifting forks 314 lie in a vertical plane. The mobile storage cart 400may include vertically-oriented fork slots 450 that are structurallyconfigured to receive the vertically-oriented cart lifting forks 314.

Furthermore, referring to FIGS. 2-5 and 10, the vehicle-based cartengagement hardware 316 may comprise anti-rock cart engagement hardware340 configured to engage a top end 401 of the mobile storage cart 400.The vehicular controller(s) may be in communication with thevehicle-based cart engagement hardware 316 and may execute vehiclefunctions to use the vehicle-based cart engagement hardware 316 toengage a mobile storage cart 400 with the one or more cart lifting forks314 and the anti-rock cart engagement hardware 340 of the fork carriageassembly 310.

The anti-rock cart engagement hardware 340 may comprise a pair ofsupport arms 342 configured to engage a top end 401 of the mobilestorage cart 400. The anti-rock cart engagement hardware 340 maycomprise lateral anti-rock hardware wherein each support arm 342comprises a hook subtending extension 348, and the mobile storage cart400 comprises a pair of extension passages 408 structurally configuredto permit the hook subtending extensions 348 to pass at least partiallythrough the pair of extension passages 408. The anti-rock cartengagement hardware 340 may comprise front-rear anti-rock hardwarewherein each support arm 342 comprises an anti-rock hook 344 defining anotch 345, the anti-rock hook 344 extends downwardly at a distal portion346 of the support arm 342 to define an engagement gap between the hooksubtending extension 348 and a terminal portion of the anti-rock hook344. The mobile storage cart 400 may comprise hook engaging featuresstructurally configured to engage the anti-rock hooks 344 of the pair ofsupport arms 342. The pair of extension passages 408 are structurallyconfigured to permit the hook subtending extensions 348 to pass at leastpartially through the pair of extension passages 408 to permit theanti-rock hooks 344 of the pair of support arms 342 to engage the hookengaging features of the mobile storage cart 400 while the pair ofsupport arms 342 engage a top end 401 of the mobile storage cart 400.The extension passage 408 spacing is approximately equal to the spacingof the pair of support arms 342, and the extension passages 408 arelarge enough to permit the support arms 342 to pass therethrough.

Each support arm 342 may include an anti-rock hook 344 defining a notch345, and a hook subtending extension 348. The anti-rock hook 344 mayextend downwardly at a distal portion 346 of the support arm 342 todefine an engagement gap between the hook subtending extension 348 and aterminal portion of the anti-rock hook 344. The hook engaging featuresmay be structurally configured to engage the anti-rock hooks 344 of thepair of support arms 342. Furthermore, the mobile storage cart 400 maycomprise a pair of extension passages 408 structurally configured topermit the hook subtending extensions 348 to pass at least partiallythrough the pair of extension passages 408 to permit the anti-rock hooks344 of the pair of support arms 342 to engage the hook engaging featuresof the mobile storage cart 400. In some embodiments, the hook engagingfeatures may include vertical prongs 406.

Referring still to FIGS. 2-5 and 10, the anti-rock cart engagementhardware 340 may comprise a pair of support arm engagement features 402disposed at and extending from a top end 401 of a mobile storage cart400 which is supported by the cart lifting forks 314. Each support armengagement feature 402 may include a horizontal lip 404 and a verticalprong 406. The horizontal lip 404 is configured to be supported on thehook subtending extension 348 of the support arm 342, and the verticalprong 406 is configured to be received and supported by the notch 345 inthe anti-rock hook 344. In embodiments, the anti-rock cart engagementhardware 340 is configured to engage the mobile storage cart 400. Inanother embodiment, the anti-rock cart engagement hardware 340 isconfigured to engage the mobile storage cart 400 supported by the cartlifting forks 314. By way of example and not as a limitation, theanti-rock cart engagement hardware 340 is configured to engage themobile storage cart 400 supported by the cart lifting forks 314 at acart contact point that is vertically displaced from the mobile storagecart support platform 312 by a distance approximating a height of themobile storage cart 400. In another embodiment, the anti-rock cartengagement hardware 340 may be configured to engage the mobile storagecart 400 supported by the cart lifting forks 314 at a pair of cartcontact points that are vertically displaced from the mobile storagecart support platform 312 by a distance approximating a height of themobile storage cart 400.

It should be understood that different suitable variations of thesemobile storage carts to be engaged with the cart lifting forks 314 arewithin the scope of this disclosure. For example, the mobile storagecart 400 may also include a wired grid, plexiglass, or mesh insert alongthe sides of shelving of the mobile storage cart 400 not configured toface the materials handling vehicle 300 when engaged.

Referring to FIGS. 1I, 5, 5A, 5B, 6, and 12, as previously stated, thematerials handling vehicle 300 includes a cart engagement subsystem 350(shown in FIG. 12). The cart engagement subsystem 350 is characterizedby a storage cart engagement field of view 352 (shown in FIGS. 5A and5B). The storage cart engagement field of view 352 may be defined by avision system 354 (shown in FIG. 6) within the cart engagement subsystem350. Referring to FIGS. 1I, 5, 5A and 12, the vehicular controller(s) ofthe materials handling vehicle 300 execute vehicle functions to: (i) usethe navigation subsystem 360 to navigate the materials handling vehicle300 along the inventory transit surface 110 to a localized engagementposition where a cart home position 410 (as shown in FIG. 1I) is withinthe storage cart engagement field of view 352 (as shown in FIG. 5A), and(ii) use the cart engagement subsystem 350 to engage the mobile storagecart 400 in the cart home position 410 with the fork carriage assembly310.

Referring to FIGS. 1I, 5, 5A, 5B, 6, and 12, the cart engagementsubsystem 350 may be operatively coupled to at least one of the tractioncontrol unit 372, the braking system 371, the steering assembly 373, themast assembly control unit 374, the carriage control unit 375, cartengagement sensors 355, and the picking attachment 320 to facilitatecart engagement. The cart engagement subsystem 350 may be coupled tothese components directly, or indirectly, through the vehicularcontroller(s). The cart engagement subsystem 350 may be furthercharacterized by a close approach field of view 358 (shown in FIGS. 5Aand 5B) that is more restricted than the cart engagement field of view352 (also shown in FIGS. 5A and 5B). The cart engagement subsystem 350may transition from an initial approach mode in the cart engagementfield of view 352 to a close approach mode in the close approach fieldof view 358 as the cart home position 410 moves into the close approachfield of view 358 (shown in FIG. 5A).

For example, the materials handling vehicle 300 navigates to thelocation of the mobile storage cart 400 using the navigation subsystem360 and positions the materials handling vehicle 300 in the localizedengagement position. From there, the cart engagement subsystem 350 usescart engagement sensors 355 (shown in FIG. 5B) to identify the mobilestorage cart 400 in the initial approach mode. The cart engagementsensors 355 may be positioned within a hollow body portion of a monoforkcarriage assembly of a materials handling vehicle 900 (as will besubsequently described), as shown in FIGS. 5A and 5B. In alternativeembodiments, the cart engagement sensors 355 may be positioned on thefork side 303 of the materials handling vehicle 300 (as shown in FIG.5C). The cart engagement sensors 355 may include lasers, proximitysensors, cameras, or combinations thereof. The cart engagement sensors355 may be capable of detecting the presence of a mobile storage cart400 without any physical contact. In embodiments, the cart engagementsensors 355 may detect the mobile storage cart 400 by emitting anelectromagnetic field and detecting changes in the electromagneticfield. Similarly, the cart engagement sensors 355 may detect the mobilestorage cart 400 by emitting a beam of electromagnetic radiation (suchas an infrared laser beam) and detecting changes in the return beam.Similar cameras and imaging equipment are disclosed in U.S. Pat. Nos.9,990,535 B2 and 9,087,384 B2.

The cart engagement subsystem 350 uses the cart engagement sensors 355to make course adjustments to align the cart lifting forks 314 to thevertically oriented fork slots 450 of the mobile storage cart 400 in theinitial approach mode. Once the cart engagement field of view 352 nolonger detects the mobile storage cart 400, the cart engagementsubsystem 350 transitions from the initial approach mode to the closeapproach mode and makes fine adjustments to the alignment of the cartlifting forks 314 and the vertically oriented fork slots 450. The cartengagement subsystem 350 remains in the close approach mode until thecart engagement sensors 355 indicate the mobile storage cart 400 iscoupled to the materials handling vehicle 300.

When the materials handling vehicle 300 sets down a mobile storage cart400 the cart engagement subsystem 350 starts in a reverse equivalent ofthe close approach mode and makes fine adjustments to maintain thealignment of the cart lifting forks 314 and the vertically oriented forkslots 450 of the mobile storage cart 400 as the materials handlingvehicle 300 backs away from the mobile storage cart 400. The cartengagement subsystem 350 then transitions to a reverse equivalent of theinitial approach mode and the mobile storage cart 400 moves out of theclose approach field of view 358. This mode can be maintained until themobile storage cart 400 moves out of the engagement field of view 352(or out of some other predetermined distance, e.g. from 1 meter to 3meters) at which point the cart engagement subsystem 350 may halt andallow the navigation subsystem 360 to control navigation. It iscontemplated that this localized engagement position is recorded forfuture cart engagement by the materials handling vehicle 300.

Referring to FIGS. 1I and 12, the navigation subsystem 360 may compriseone or more environmental sensors and an environmental database. Inembodiments, the environmental sensors are configured to capture dataindicative of a position of the materials handling vehicle 300 relativeto the multilevel warehouse racking system 200, the inventory transitsurface 110, or both. Further, the environmental database may comprisestored data indicative of the multilevel warehouse racking system 200,the inventory transit surface 110, or both. The navigation subsystem 360may be configured to enable at least partially automated navigation ofthe materials handling vehicle 300 along the inventory transit surface110 utilizing the captured data and the stored data. For example, andnot by way of limitation, it is contemplated that the navigationsubsystem 360 may utilize a stored warehouse map and captured images ofceiling lights or sky lights to enable navigation, as is disclosed inU.S. Pat. No. 9,174,830 issued on Nov. 3, 2015, (CRNZ 0053 PA), U.S.Pat. No. 9,340,399 issued on May 17, 2016 (docket no. CRNZ 0053 NA), andother similar patents and patent publications. Additional suitableenvironmental sensors include, but are not limited to, inertial sensors,lasers, antennae for reading RFID tags, buried wires, WiFi signals, orradio signals, global positioning system (GPS) sensors, globalnavigation satellite system (GNSS) sensors, or combinations thereof.

In embodiments, a warehouse map is stored in a memory that iscommunicatively coupled to the vehicular controller(s). The vehicularcontroller(s) of the materials handling vehicle 300 may execute vehiclefunctions to use the navigation subsystem 360 to determine a localizedposition of the materials handling vehicle 300 with respect to theinventory transit surface 110 of a warehouse based on a position of thematerials handling vehicle 300 in the warehouse in comparison with thewarehouse map. The vehicular controller(s) of the materials handlingvehicle 300 may further execute vehicle functions to use the navigationsubsystem 360 to track navigation of the materials handling vehicle 300along the inventory transit surface 110 based on the localized position,navigate the materials handling vehicle 300 along the inventory transitsurface 110 in at least a partially automated manner, or both.

The navigation subsystem 360 may be operatively coupled to at least oneof the traction control unit 372, the braking system 371, the steeringassembly 373, the mast assembly control unit 374, the carriage controlunit 375, and the picking attachment 320 to facilitate cart engagement.Further, the navigation subsystem 360 may be coupled to these componentsdirectly, or indirectly, through the vehicular controller(s).

As stated previously, the materials handling vehicle comprises a pickingattachment. Referring further to FIG. 5, the picking attachment 320 maycomprise an X-Y-Z-Ψ positioner 322 and the vehicular controller(s) ofthe materials handling vehicle 300 may execute vehicle functions to usethe X-Y-Z-Ψ positioner 322 of the picking attachment 320 to engage anddisengage a target tote 214 positioned in the multilevel warehouseracking system 200 with the picking attachment 320.

As illustrated in FIG. 6, the X-Y-Z-Ψ positioner 322 may comprise anX-positioner 323 configured to move the picking attachment 320 in afirst degree of freedom along a first lateral axis 324 in a lateralplane, a Y-positioner 325 configured to move the picking attachment 320in a second degree of freedom along a second lateral axis 326perpendicular to the first lateral axis 324 in the lateral plane, aZ-positioner 327 configured to move the picking attachment 320 in athird degree of freedom along a Z-axis 328 perpendicular to the firstlateral axis 324 and the second lateral axis 326, and a rotationalΨ-positioner 329 configured to rotate the picking attachment 320 in afourth degree of freedom about the Z-axis 328. The X-positioner 323 maycomprise rails 330 configured to permit movement of the pickingattachment 320 along the first lateral axis 324. The Y-positioner 325may comprise rails 331 configured to permit movement of the pickingattachment 320 along the second lateral axis 326. The Z-positioner 327may comprise a vertical displacement mechanism configured to slidablyengage with a post 332 of the fork carriage assembly 310 for verticaldisplacement with respect to the fork carriage assembly 310. Therotational Ψ-positioner 329 may comprise a shaft 333 configured topermit rotation of the picking attachment 320 about the Z-axis 328. Such“rails” may include mechanical engagement components such as one or moretracks fixed on an upright support, each including an engagementmechanism configured to engage with a corresponding engagement mechanismof a respective positioner for a sliding engagement. For example, anengagement mechanism of a rail may be one of a notch or a protrusionconfigured to slidably engage with the notch, and the correspondingengagement mechanism may be the other of the notch or the protrusion. Asa non-limiting example, the tracks may be bars made of metal such asstainless steel or a suitable material understood to be within the scopeof this disclosure.

The materials handling vehicle 300 may further comprise a pickingattachment subsystem 321, which is illustrated schematically in FIG. 12,in communication with the vehicular controller(s) of the materialshandling vehicle 300. As is illustrated in FIG. 6, the pickingattachment subsystem 321 comprises the picking attachment 320 (includingthe X-Y-Z-Ψ positioner 322) and a time-of-flight (TOF) system 356. Thepicking attachment subsystem 321 is configured to use the TOF system 356to generate a target TOF depth map of a target tote 214 (shown in FIG.6). In embodiments, the target tote 214 may be positioned in a shelfunit 217 of a rack bay 218 of the rack module 211 (as shown in FIG. 7).Additionally or alternatively, the target tote 214 may be positioned inthe tote transfer zone 219 (as shown in FIGS. 1I, 1G, and 1H). Inembodiments, the target tote 214 may be positioned on the transporter(not shown). Referring to FIGS. 6-8, the vehicular controller(s) of thematerials handling vehicle 300 may execute vehicle functions to use theX-Y-Z-Ψ positioner 322 of the picking attachment subsystem 321 to engagethe target tote 214 with the picking attachment 320 based on the targetTOF depth map. For example, the picking attachment 320 engages thetarget tote 214 or a target pallet with the aid of a TOF depth map,which is particularly useful for rotational (Ψ) positioning about the Zaxis. Rotational adjustments may compensate for target tote 214 rotationor rotational error in the materials handling vehicle 300. Thenavigation subsystem 360 may be configured to position the materialshandling vehicle 300 such that the target tote 214 is within a toteengagement field of view 351 of the TOF system 356.

Referring to FIGS. 1I, 6-8, and 12, the vision system 354 may also bepart of the navigation subsystem 360, and the multilevel warehouseracking system may comprise a target fiducial 216 associated with thetarget tote 214. The navigation subsystem 360 may be configured toposition the materials handling vehicle 300 such that the targetfiducial 216 is within a field of view of the vision system 354 tovisualize the target fiducial 216 for identification purposes. Thenavigation subsystem 360 may further be configured to utilize the targetfiducial 216 to position the materials handling vehicle 300 such thatthe target tote 214 is within the tote engagement field of view 351 ofthe TOF system 356. In embodiments, the vision system 354 may beconfigured to read the target fiducial 216 to identify the target tote214 and verify that the correct target tote 214 is within the field ofview of the vision system 354. For example, it is contemplated thatsuitable target fiducials 216 may include markings or tags on themultilevel warehouse racking system 200, or distinctive elements of themultilevel warehouse racking system 200 itself. The target fiducial 216may be a barcode or any other two-dimensional visual machine-readabledata representation. An example is depicted in FIG. 7 with respect to atarget fiducial 216 disposed on a rack module 211 such as a shelf unit217. Rack modules within the scope of this disclosure may have differentnumbers of slots to position items such as totes within, and a fiducialsuch as the target fiducial 216 attached to each rack module 211 may beconfigured to identify the number of slots per respective module. Once aposition of the target fiducial 216 is recorded as an X-Y-Z position onthe warehouse map, a position of the totes (including, for example, thetarget tote 214) within the shelf unit 217 will be known as well. Anentire rack module including or empty of one or more totes may be pickedas described herein from a storage location such as the shelf unit 217or a target tote 214 may be individually picked as described herein. Atarget tote 214 to be picked may not include a target fiducial 216 butmay be stored in a storage location such as a shelf unit 217 thatincludes the target fiducial 216 to guide the materials handling vehicle300 to the localized position of the shelf unit 217 to engage the targettote 214 as described herein. Alternatively, both the rack module 211,such as the shelf unit 217, and the target tote 214 may include targetfiducials 216 to guide engagement of the target tote 214 with thepicking attachment 320 as described herein.

With reference to FIGS. 7, 8, 9 and 12, a picking scheme as describedherein may include travel to a tote location 215 of a target tote 214within a rack module 211 to engage the target tote 214. In otherembodiments, the target tote 214 may be positioned in the tote transferzone or positioned on the transporter as previously described. Anotherpicking scheme may include travel to a rack module 211 within a rack bay218 of the multilevel warehouse racking system 200 and visualization ofa target fiducial 216 of the rack module 211 to pick, based on, forexample, known coordinates of the target fiducial 216, the entire rackmodule 211 or a target tote 214 from within the rack module 211.Further, a picking scheme may include dual target fiducial visualizationand include travel to a rack module 211 within a rack bay 218 of themultilevel warehouse racking system 200, visualization of a targetfiducial 216 of the rack module 211, movement to a location of a targettote 214 within the visualized rack module 211 based on informationreceived from visualization of that rack module 211, visualization ofthe target tote 214 within the rack module 211, and engagement of thetarget tote 214 by the picking attachment 320 as described herein. Thus,the navigation subsystem 360 may be configured to position the materialshandling vehicle 300 such that the target fiducial 216 of a shelf unit217 of the rack module 211 is within a field of view of the visionsystem 354. The navigation subsystem 360 may additionally be configuredto utilize the target fiducial 216 to position the materials handlingvehicle 300 such that the shelf unit 217 is within a rack module fieldof view of the TOF system 356. The navigation subsystem 360 may furtherbe configured to utilize a target fiducial 216 of the target tote 214within the rack module 211 field of view to position the materialshandling vehicle 300 such that the target tote 214 is within the toteengagement field of view 351 of the TOF system 356.

As illustrated in FIGS. 7 and 8, the target tote 214 may be storedwithin a rack module 211 such as on a shelf unit 217 of the multilevelwarehouse racking system 200. In FIG. 7, the picking attachment 320 ofthe materials handling vehicle 300 of FIG. 5 is in a position in which aslide-out 334 of the picking attachment 320 is in an extended positionto either retrieve the target tote 214 from or store the target tote 214on the shelf unit 217. In FIG. 8, the materials handling vehicle 300 ofFIG. 5 is in a position in which the slide-out 334 has positioned thetarget tote 214 in the picking attachment 320 in a secured position. InFIG. 9, the materials handling vehicle 300 of FIG. 5 is in a position inwhich the picking attachment 320 is in rotational alignment, through arotation as described in greater detail below, with a shelf of theengaged mobile storage cart 400, and the slide-out 334 is in an extendedposition to either retrieve the target tote 214 from or store the targettote 214 on the shelf of the engaged mobile storage cart 400.

Referring to FIG. 1I, the picking scheme as described in reference to atarget tote 214 positioned within the shelf unit 217 as shown in FIGS.7, 8, 9 and 12 may be similarly applied to a target tote 214 positionedin the tote transfer zone 219 or positioned on the lifting surface ofthe transporter 500. In such embodiments, the picking attachment 320 may(i) transfer the target tote 214 between multiple levels of themultilevel warehouse racking system 200 and the transporter 500, (ii)transfer the target tote 214 between multiple levels of the multilevelwarehouse racking system 200 and the tote transfer zone 219, (iii)transfer the target tote 214 between the tote transfer zone 219 and thetransporter 500, and (iv) transfer the target tote 214 between thetransporter 500 and the mobile storage cart 400 when the mobile storagecart 400 is engaged by the materials handling vehicle 300.

Referring now to FIGS. 5, 12, and 13, in embodiments, a hand-held driveunit 370 is secured to the vehicle body 301 and comprises a userinterface 388 and an operational command generator 389 that isresponsive to the user interface 388. In alternative embodiments, thehand-held drive unit 370 may be remote from and not secured to thevehicle body 301.

The operational command generator 389 may comprise any suitablecombination of conventional, or yet-to-be developed, circuitry andsoftware that enables the hand-held drive unit 370 to send operationalcommands generated in response to user input at the user interface 388to the vehicular controller(s) to control operational functions of thetraction control unit 372, the braking system 371, the steering assembly373, the mast assembly 302 through the mast assembly control unit 374,the picking attachment 320, or combinations thereof. The hand-held driveunit 370 may be secured to the vehicle body 301 so as to be accessiblefor removal from the vehicle body 301 from the power unit side 304 ofthe vehicle body 301 by an operator sharing (such as positioned on) theinventory transit surface with the wheels 306 supporting the vehiclebody 301.

The vehicle body 301 may also comprise a pair of lateral sides 305extending between the fork side 303 and power unit side 304 of thevehicle body 301, with the lateral sides 305 defining a vehicle widthw₁. In narrow aisle environments, where when the materials handlingvehicle 300 is positioned in a warehouse aisle characterized by an aislewidth w₂, where w₂−w₁<W inches where W is in a range of from about 2inches to about 4 inches (and w₂>w₁), the hand-held drive unit 370 issecured to the vehicle body 301 so as to be accessible for removal bythe operator sharing the inventory transit surface 110 with thematerials handling vehicle 300. The equation above is an exampleequation for a maximum gap value, and values set forth are notcontemplated to a limitation. As a non-limiting example, the hand-helddrive unit 370 may be secured to a surface of the power unit side 304 ofthe vehicle body 301 and may be configured to permit an operator tofully control the materials handling vehicle 300 positioned in a firstaisle without a need for the operator to travel down an empty, adjoiningaisle next to the first aisle to get to the operator compartment 307 onthe fork side 303 of the materials handling vehicle 300. In other words,a retrofitted materials handling vehicle 300 may require manualintervention on the part of an operator and, if the operator is locatedin the first aisle on the power unit side 304 opposite from the operatorcompartment 307 and unable to fit between the vehicle body 301 and thefirst aisle, the hand-held drive unit 370 provides a way for theoperator to manually intervene without the need to get to the operatorcompartment 307. It is contemplated that all of the functionality of thehand-held drive unit 370 described herein is duplicated with usercontrols in the operator compartment 307 such that the operator maycontrol the materials handling vehicle 300 as if the operator werewithin the operator compartment 307 without actually being in theoperator compartment 307.

As previously referenced, the vehicular controller(s) may comprise apicking controller 376, a braking controller 377, a traction controller378, a steering controller 379, a mast controller 380, or one or moreintegrated controllers, to control operational functions of the pickingattachment 320, the braking system 371, traction control unit 372, thesteering assembly 373, or the mast assembly control unit 374. Where thevehicular controller(s) comprises a traction controller 378 configuredto control operational functions of the traction control unit 372, theuser interface 388 of the hand-held drive unit 370 may comprise tractioncontrol operators 384. The traction controller 378 may be responsive tooperational commands generated with the traction control operators 384of the hand-held drive unit 370. For example, it is contemplated thatthe traction control operators 384, and other types of control operatorsdescribed herein, can be implemented in a variety of ways, such as viavirtual buttons provided on a touch screen display 390, physical inputs391 located on the hand-held drive unit 370 (such as buttons, joysticks,etc.), any of which may be dedicated or customizable. It iscontemplated, for example, that the physical inputs 391 may becustomized using configurable menu options, scrolling interfaces, orother on-screen options provided at the touch screen display 390. It isalso contemplated that the body of the hand-held drive unit 370 could beused as a control operator if the unit were to be provided with one ormore motion sensors, such as a gyroscope, accelerometer, etc., to detectmovement and/or rotation of the hand-held drive unit 370. In furthercontemplated embodiments, gesture tracking, gaze tracking, voicecontrol, and other types of indirect control operators may be used.

The vehicular controller(s) may also comprise a braking controller 377configured to control operational functions of the braking system 371.The user interface 388 of the hand-held drive unit 370 may comprisebraking control operators 383. The braking controller 377 may beresponsive to operational commands generated with the braking controloperators 383 of the hand-held drive unit 370.

Similarly, the vehicular controller(s) may comprise a steeringcontroller 379 configured to control operational functions of thesteering assembly 373. In which case, the user interface 388 of thehand-held drive unit 370 would comprise steering control operators 385,and the steering controller 379 would be responsive to operationalcommands generated with the steering control operators 385.

The vehicular controller(s) may also comprise a mast controller 380configured to control operational functions of the mast assembly controlunit 374 that is configured to control the mast assembly 302. In whichcase, the user interface 388 of the hand-held drive unit 370 wouldcomprise mast assembly control operators 386, and the mast controller380 would be responsive to operational commands generated with the mastassembly control operators 386.

The vehicular controller(s) may additionally comprise a pickingcontroller 376 configured to control operational functions of thepicking attachment 320. In which case, the user interface 388 of thehand-held drive unit 370 would comprise picking attachment controloperators 382, and the picking controller 376 would be responsive tooperational commands generated with the picking attachment controloperators 382.

The vehicular controller(s) may additionally comprise a carriagecontroller 381 configured to control operational functions of thecarriage control unit 375, which is configured to control the forkcarriage assembly 310. In which case, the user interface 388 of thehand-held drive unit 370 would comprise carriage control operators 387,and the carriage controller 381 would be responsive to operationalcommands generated with the carriage control operators 387.

The materials handling vehicle 300 may further comprise a camera 308coupled to the fork carriage assembly 310, with the camera 308 beingconfigured to send image data representing objects within a field ofview of the camera 308 to the hand-held drive unit 370. The hand-helddrive unit 370 may comprise a touch screen display 390 or other type ofdisplay for displaying image data representing objects within the fieldof view of the camera 308. In this manner, a ground-based operator canuse the image data as an aide to using the hand-held drive unit 370 tocontrol various functions of the materials handling vehicle 300. This isparticularly advantageous where the field of view of the camera 308extends beyond the field of view of an operator sharing an inventorytransit surface 110 with the materials handling vehicle 300. In someembodiments, the hand-held drive unit 370 may be configured to allow anoperator to view images of the picking attachment 320 and sendoperational commands to the picking controller 376 through pickingattachment control operators 382 of the hand-held drive unit 370 tocontrol operational functions of the picking attachment 320.

It is also contemplated that the hand-held drive unit 370 may beconfigured to control the field of view of the camera 308. For example,the field of view of the camera 308 may be controlled by changing theposition or orientation of the camera 308, by controlling the zoom ofthe camera optics, by controlling an aiming direction of the cameraoptics, or combinations thereof. In various embodiments, the hand-helddrive unit 370 is configured to control focusing optics of the camera308. In other embodiments, the camera 308 may be coupled to the forkcarriage assembly 310 by a camera positioner 309, and the hand-helddrive unit 370 may be configured to control the operational functions ofthe camera positioner 309.

It is also contemplated that the camera 308 may be coupled to the forkcarriage assembly 310 either internally or externally. Aninternally-coupled camera could reside at least partially within thefork carriage assembly 310, such as with a pinhole camera. Anexternally-coupled camera may be attached to the fork carriage assembly310 by any suitable means, such as with coupling mechanisms (screws,bolts, etc.), attachment mechanisms (camera base-mounts, brackets,etc.), adhesives, or combinations thereof.

In many cases, it will be advantageous to ensure that the hand-helddrive unit 370 is secured to a surface of the vehicle body 301 that isnot located within a path of vertical movement of the fork carriageassembly 310. In this manner, by ensuring that the hand-held drive unit370 is accessible from the power unit side 304, and not the fork side303 of the materials handling vehicle 300, the operator will not berequired to walk under the fork carriage assembly 310 to access thehand-held drive unit 370. In some embodiments, it may be sufficient tomerely ensure that the hand-held drive unit 370 is secured to a surfaceof the vehicle body 301 that is not located at the fork side 303 of thevehicle body 301. In other embodiments, it may be advantageous to ensurethat the hand-held drive unit 370 is held within a drive unit case 392,and the drive unit case 392 is secured to the vehicle body 301. Forexample, referring to FIG. 5, the materials handling vehicle 300includes the drive unit case 392 housing the hand-held drive unit 370 atthe power unit side 304 of the materials handling vehicle 300.

It is contemplated that the hand-held drive unit 370 described above maybe secured to the materials handling vehicle 300, or may be present at alocation remote from the materials handling vehicle 300. Further, thefunctionality of the hand-held drive unit 370 may be presented morebroadly in the form of a remote controller that is communicativelycoupled to the materials handling vehicle 300 through, for example, awireless communication link. The remote controller may or may not be ahand-held and may or may not be secured to the materials handlingvehicle 300. The remote controller may comprise a video link to displayimage data from the camera 308. Contemplated remote controllers may, forexample, be presented as a desktop computer, a laptop computer, asmartphone, a tablet, a wearable computing device, or some combinationthereof. It is also contemplated that the remote controller, whetherhand-held or not, may be utilized in a dual mode operation where usercontrol is facilitated from two separate remote controllers. Forexample, and not by way of limitation, in one type of dual modeoperation, a user is able to control vehicular operations through aremote controller at a remote location, such as through a laptopcomputer, while also permitting the same or another user to sign inthrough a secured webpage or a software application loaded on asmartphone, or other hand-held device, to control such vehicularoperations. Regardless of the mode of operation, it is contemplated thatthe remote controller may be utilized by an operator at a location thatis remote from the materials handling vehicle 300, or by an operatorsharing the inventory transit surface 110 with the materials handlingvehicle 300.

In FIG. 1I, the goods receiving station 610 comprises a goods selectionterminal 620 that is outfitted for removal of totes from the mobilestorage carts 400 or from the transporters 500. In an alternativeembodiment, the goods-to-man warehousing system 600 further comprises anintermediate transfer station 630 that is positioned along a mobilestorage cart travel path extending from the mobile storage cart transfernode 420 to the goods receiving station 610. The mobile storage carts400 may be positioned at the intermediate transfer station 630 and maybe transferred from the goods receiving station 610 at the intermediatetransfer station 630 to the goods selection terminal 620 by thetransporter 500.

Referring now to FIGS. 1A and 1B, the goods selection terminal comprisesan operator platform 622 above an inventory transit surface 110 of thegoods storage and retrieval system 100. The operator platform 622comprises a goods access portal 624 that is accessible by an operator625 from above the operator platform 622 and by the transporter 500 frombelow the operator platform 622. As shown in FIG. 1A, the transporter500 may be configured to elevate the transporter lifting surface to aheight of the operator platform 622. In embodiments, the height of theoperator platform 622 may be approximately equal to the transportingheight of the transporter 500. When the transporter lifting surface iselevated to the height of the operator platform 622, the target tote 214may be accessed by the operator 625. In an alternative embodiment, shownin FIG. 1B, the goods selection terminal 620 comprises a transporterraising surface 626 that is flush with the inventory transit surface110, aligned with the goods access portal 624, and configured to elevatethe transporter 500 from the inventory transit surface 110 of the goodsstorage and retrieval system 100 to the operator platform 622. When thetransporter 500 is elevated to the operator platform 622, the targettote 214 may be accessed by the operator 625.

Referring again to FIG. 1I, the warehouse management computing hub is incommunication with the transporter 500 and the materials handlingvehicle 300, and is be programmed to instruct the transporter 500 andthe materials handling vehicle 300 to coordinate engagement, transport,and disengagement of the mobile storage carts 400 and the target tote inthe goods-to-man warehousing system 600. The warehouse managementcomputing hub may be configured to manage locations of the plurality ofmobile storage carts 400, the transporters 500, the materials handlingvehicles 300, the mobile storage cart transfer nodes 420, and the goodsreceiving stations 610. More specifically, the aforementionedcoordinated movement may apply to the transfer of the mobile storagecarts 400 between the aisles 220 of the multilevel warehouse rackingsystem 200, the materials handling vehicle 300, the mobile storage carttransfer node 420, the transporter 500, the goods receiving station 610,or various combinations thereof. In addition, it is contemplated thatthese instructions may be presented in a variety of forms. For example,and not by way of limitation, these instructions may represent detailedturn-by-turn movements for the transporter 500 and materials handlingvehicle 300 to accomplish the aforementioned coordination. Or, theinstructions may merely represent a set of position and time coordinatesnecessary to accomplish the aforementioned coordination. In which case,the transporter 500 and materials handling vehicle 300 would beresponsible for developing their own turn-by-turn travel paths toaccomplish the aforementioned coordination. In any case, it iscontemplated that those practicing the concepts of the presentdisclosure may rely on conventional or yet-to-be developed teachingsrelated to warehouse traffic management and automated vehicle guidanceto achieve the aforementioned coordination.

Referring to FIG. 14, a block diagram illustrates a computing device700, through which embodiments of the disclosure can be implemented. Thecomputing device 700 described herein is but one example of a suitablecomputing device and does not suggest any limitation on the scope of anyembodiments presented. For example, the computing device 700 in someembodiments is an example of the remote controller such as the hand-helddrive unit described herein and/or other suitable mobile client devicesthat may be communicatively coupled to the hand-held drive unit. Thecomputing device 700 may be communicatively coupled to one or morecomputing devices through a warehouse management system. Nothingillustrated or described with respect to the computing device 700 shouldbe interpreted as being required or as creating any type of dependencywith respect to any element or plurality of elements. In variousembodiments, a computing device 700 may include, but need not be limitedto, a desktop, laptop, server, client, tablet, smartphone, or any othertype of device that can compress data. In an embodiment, the computingdevice 700 includes at least one processor 702 and memory (non-volatilememory 708 and/or volatile memory 710). In embodiments, the one or moretarget TOF depth maps 353 and/or one or more warehouse maps 362described herein may be stored in the memory. The computing device 700can include one or more displays (such as the touch screen display ofthe hand-hand drive unit) and/or output devices 704 such as monitors,speakers, headphones, projectors, wearable-displays, holographicdisplays, and/or printers, for example. Output devices 704 may beconfigured to output audio, visual, and/or tactile signals and mayfurther include, for example, audio speakers, devices that emit energy(radio, microwave, infrared, visible light, ultraviolet, x-ray and gammaray), electronic output devices (Wi-Fi, radar, laser, etc.), audio (ofany frequency), etc.

The computing device 700 may further include one or more input devices706 which can include, by way of example, any type of mouse, keyboard,disk/media drive, memory stick/thumb-drive, memory card, pen,touch-input device, biometric scanner, voice/auditory input device,motion-detector, camera, scale, and the like. Input devices 706 mayfurther include sensors, such as biometric (voice, facial-recognition,iris or other types of eye recognition, hand geometry, fingerprint, DNA,or any other suitable type of biometric data, etc.), video/still images,motion data (accelerometer, GPS, magnetometer, gyroscope, etc.) andaudio (including ultrasonic sound waves). Input devices 706 may furtherinclude cameras (with or without audio recording), such as digitaland/or analog cameras, still cameras, video cameras, thermal imagingcameras, infrared cameras, cameras with a charge-couple display,night-vision cameras, three-dimensional cameras, webcams, audiorecorders, and the like. For example, an input device 706 may includethe camera 308 described herein.

The computing device 700 typically includes non-volatile memory 708(ROM, flash memory, etc.), volatile memory 710 (RAM, etc.), or acombination thereof. A network interface hardware 712 can facilitatecommunications over a network 714 via wires, via a wide area network,via a local area network, via a personal area network, via a cellularnetwork, via a satellite network, etc. Suitable local area networks mayinclude wired Ethernet and/or wireless technologies such as, forexample, wireless fidelity (Wi-Fi). Suitable personal area networks mayinclude wireless technologies such as, for example, IrDA, Bluetooth,Wireless USB, Z-Wave, ZigBee, and/or other near field communicationprotocols. Suitable personal area networks may similarly include wiredcomputer buses such as, for example, USB and FireWire. Suitable cellularnetworks include, but are not limited to, technologies such as LTE,WiMAX, UMTS, CDMA, and GSM. Network interface hardware 712 can becommunicatively coupled to any device capable of transmitting and/orreceiving data via the network 714. Accordingly, the network interfacehardware 712 can include a communication transceiver for sending and/orreceiving any wired or wireless communication. For example, the networkinterface hardware 712 may include an antenna, a modem, LAN port, Wi-Ficard, WiMax card, mobile communications hardware, near-fieldcommunication hardware, satellite communication hardware and/or anywired or wireless hardware for communicating with other networks and/ordevices.

A computer-readable medium 716 may comprise a plurality of computerreadable mediums, each of which may be either a computer readablestorage medium or a computer readable signal medium. Thecomputer-readable medium 716 may be non-transitory in that it excludesany transitory, propagating signal as a storage medium and may reside,for example, within an input device 706, non-volatile memory 708,volatile memory 710, or any combination thereof. A computer readablestorage medium can include tangible media that is able to storeinstructions associated with, or used by, a device or system. A computerreadable storage medium includes, by way of example: RAM, ROM, cache,fiber optics, EPROM/Flash memory, CD/DVD/BD-ROM, hard disk drives,solid-state storage, optical or magnetic storage devices, diskettes,electrical connections having a wire, or any combination thereof. Acomputer readable storage medium may also include, for example, a systemor device that is of a magnetic, optical, semiconductor, or electronictype. Computer readable storage media and computer readable signal mediaare mutually exclusive.

A computer readable signal medium can include any type of computerreadable medium that is not a computer readable storage medium and mayinclude, for example, propagated signals taking any number of forms suchas optical, electromagnetic, or a combination thereof. A computerreadable signal medium may include propagated data signals containingcomputer readable code, for example, within a carrier wave. Computerreadable storage media and computer readable signal media are mutuallyexclusive.

The computing device 700 may include one or more network interfacehardwares 712 to facilitate communication with one or more remotedevices, which may include, for example, client and/or server devices. Anetwork interface hardware 712 may also be described as a communicationsmodule, as these terms may be used interchangeably. For clarity, it isnoted that usage of the term “in communication with” herein, withrespect to the FIG. 14, or elsewhere, may refer to one-way communicationor two-way communication.

A method 800 of operating the goods storage and retrieval system 100according to one embodiment of the present disclosure is illustrated inFIG. 15 and may be read in light of the goods storage and retrievalsystem 100 components of FIGS. 1 and 12. As illustrated in FIG. 15, themethod 800 includes a step 802 to start cart acquisition followed by astep 804 to receive information regarding a localized engagementposition of the cart home position 410. The method 800 further includesin step 806, and through use of the navigation subsystem 360 and thevehicular controller(s), navigating the materials handling vehicle 300along the inventory transit surface 110 to a localized engagementposition and receiving information from the storage cart engagementfield of view in step 808. If in step 810 the cart home position 410 isnot within the storage cart engagement field of view 352, the method 800returns to step 806. Otherwise, if in step 810 the cart home position410 is within the storage cart engagement field of view 352, the method800 continues on to step 810 and uses the cart engagement subsystem 350to engage the mobile storage cart 400 by engaging the mobile storagecart 400 in the cart home position 410 with the fork carriage assembly310.

In embodiments, a method 820 of operating the goods storage andretrieval system 100 may include, as illustrated in FIG. 16, a step 822to start tote engagement followed by a step 824 to receive informationregarding a target tote position of a target tote 214. The method 820further includes, in step 826, and through use of at least one of thenavigation subsystem 360, the picking attachment subsystem 321, and thevehicular controller(s), navigating the materials handling vehicle 300toward the target tote position and aligning the picking attachment 320with the target tote 214. In step 828, information is received from thetote engagement field of view 351. If in step 830 the target toteposition is not within the tote engagement field of view 351, the method820 returns to step 826. Otherwise, if in step 830 the target toteposition is within the tote engagement field of view 351, the method 820continues on where the navigation subsystem 360 positions the materialshandling vehicle 300 such that the target fiducial 216 is within a fieldof view of the vision system 354 to visualize the target fiducial 216for identification purposes, where the vision system 360 may read thetarget fiducial 216 to identify the target tote 214 and/or verify thatthe correct target tote 214 is within the field of view of the visionsystem 354. The method 820 then continues on to step 832 to generate atarget tote depth map and, in step 834, to use the picking attachmentsubsystem 321 to engage the target tote 214 based on the target totedepth map.

With either or a combination of the methods 800 or 820, a velocitynumber may be assigned to a stock keeping unit (SKU) associated with atarget tote 214 in the multilevel warehouse racking system 200 based onan order velocity indicative of a frequency of usage parameterassociated with the target tote 214. A relatively high velocity numbermay be associated with a low storage position on a low shelf of themultilevel warehouse racking system 200, and a relatively low velocitynumber may be associated with a high storage position on a high shelf ofthe multilevel warehouse racking system 200. For example, a lowestvelocity number may be associated with a highest shelf, and a highestvelocity number may be associated with a lowest shelf.

Further, the picking attachment 320 and the fork carriage assembly 310may be used to move the target tote 214 from a portion of the multilevelwarehouse racking system 200 associated with a relatively low velocitynumber to a portion of the multilevel warehouse racking system 200associated with a relatively high velocity number based on an increasein the order velocity with respect to the target tote 214. Further, thepicking attachment 320 and the fork carriage assembly 310 may be used tomove the target tote 214 from a portion of the multilevel warehouseracking system 200 associated with a relatively high velocity number toa portion of the multilevel warehouse racking system 200 associated witha relatively low velocity number based on a decrease in the ordervelocity with respect to the target tote 214.

In embodiments, a first target tote may be engaged at a first storageposition on a high shelf associated with a relatively low velocitynumber with the picking attachment 320. The first target tote may beplaced with the picking attachment 320 in the mobile storage cart 400engaged by the fork carriage assembly 310. Further, the materialshandling vehicle 300 may be navigated to a second target tote when thesecond target tote is assigned a relatively high velocity number and iswithin a close distance to the first storage position. The second targettote may be engaged with the picking attachment 320, which may lower thesecond target tote to a low shelf associated with the relatively highvelocity number or place the second target tote in the mobile storagecart 400. For example, the materials handling vehicle 300 may benavigated to a subsequent pick location when the second target tote isplaced in the mobile storage cart 400, and the second target tote may beplaced on the low shelf associated with the relatively high velocitynumber while at the subsequent pick location.

In other embodiments, a first target tote may be engaged at a storagefirst position on a low shelf associated with the high velocity numberwith the picking attachment 320, and the picking attachment 320 mayplace the first target tote in the mobile storage cart 400 engaged bythe fork carriage assembly 310. Further, the materials handling vehicle300 may be navigated to a second target tote when the second target toteis assigned a relatively low velocity number and is within a closedistance to the first position on the low shelf to engage the secondtarget tote with the picking attachment 320 and either raise the secondtarget tote to a high shelf associated with the relatively low velocitynumber or place the second target tote in the mobile storage cart 400.For example, the materials handling vehicle 300 may be navigated to asubsequent pick location when the second target tote is placed in themobile storage cart 400, and the picking attachment 320 places thesecond target tote on the high shelf associated with the relatively lowvelocity number while at the subsequent pick location.

In embodiments, positioning the materials handling vehicle 300 may bepositioned in a first aisle of the multilevel warehouse racking system200, and one or more target totes 214 may be placed with the pickingattachment 320 in the mobile storage cart 400 engaged by the forkcarriage assembly 310. Further, the mobile storage cart 400 may be usedas a temporary storage location to level inventory when one or moreinventory orders are received such that the one or more target totes 214are shuffled between the mobile storage cart 400 and a plurality ofshelves 240 of the multilevel warehouse racking system 200 based on arespective order velocity indicative of a frequency of usage parameterassociated with each target tote 214 to optimize a usage parameter withrespect to the first aisle. Advantages from such inventory leveling mayinclude fewer trips by the materials handling vehicle 300 back and forththrough an aisle 220 and more picks and puts per distance traveled bythe picking attachment 320 of the materials handling vehicle 300 tolower a cost per pick. It is contemplated that such an inventoryleveling system may work in conjunction with a warehouse managementsystem to control product flow and optimize pick and replenishment andto organize products based on an average or known velocity based onproduct demand.

With such an inventory leveling system, a relatively low velocity numberassociated with a high shelf of the multilevel warehouse racking system200 may be assigned to a SKU associated with a first target tote that isstored in the mobile storage cart 400, and a relatively high velocitynumber associated with a low shelf of the multilevel warehouse rackingsystem 200 may be assigned to a SKU associated with a second target totestored on a high shelf of the multilevel warehouse racking system 200.Information may be received indicative of the second target tote beingstored on the high shelf. The materials handling vehicle 300 may benavigated to a location of the multilevel warehouse racking system 200associated with the high shelf during an off-peak picking time or an offshift time, and the mobile storage cart 400 engaged by the fork carriageassembly 310 may be moved to the high shelf. Once in position, thepicking attachment 320 may exchange the first target tote stored in themobile storage cart 400 with the second target tote stored on the highshelf to store the second target tote in the mobile storage cart 400.Such an exchange is to level inventory and reduce the amount of forkcarriage assembly 310 raising and lowering needed to retrieve targettotes 214. This would be particularly significant during, for example,peak periods or high volume shifts because it would reduce the timeneeded to fulfill an inventory order and the energy expended by thematerials handling vehicle 300.

In embodiments, one or more target totes 214 may be placed with thepicking attachment 320 in the mobile storage cart 400 engaged by thefork carriage assembly 310 such that the mobile storage cart 400 isutilized as a temporary storage location. The picking attachment 320pick and place operations may be interleaved by picking up and placingaway multiple target totes 214 during a single trip of the materialshandling vehicle 300 down an aisle 220 of the multilevel warehouseracking system 200.

The first aisle may comprise a very narrow aisle (VNA). Further, use ofthe mobile storage cart 400 as a temporary storage location allows formultiple picks to be made in the aisle 220 or while the fork carriageassembly 310 is raised to a high storage location to minimize energyused to raise and lower the fork carriage assembly 310. The mobilestorage cart 400 may also be used to fill multiple inventory order in abatch and deliver the entire batch to a location or to a transfer node420 for delivery to another location.

A first target tote 213 may be stored on a shelf of a plurality ofshelves 240 in the first aisle of the multilevel warehouse rackingsystem 200, and a second target tote 213 may be stored in the mobilestorage cart 400. The first target tote 213 on the shelf in a shelflocation may be engaged by the picking attachment 320 to pick up thefirst target tote 213 with the picking attachment 320, which may removethe first target tote 213 from the shelf location and place the firsttarget tote 213 on a container bay 430 of the mobile storage cart 400.The picking attachment 320 may engage the second target tote 213 storedin the mobile storage cart 400, remove the second target tote 213 fromthe mobile storage cart 400, and place the second target tote 213 in theshelf location to place away the second target tote 213.

In another embodiment, it is contemplated that the materials handlingvehicle 300 may transfer mobile storage carts 400 to the transporter500. In this embodiment, the location of the storage cart transfer node420 would correspond to the location of the transporter 500.

A transporter 500 may travel outside of an aisle 220, such as along thefloor beneath a row of mobile storage carts 400, which can help keep theaisle 220 clear as well as reduce the travel time of the transporter 500and/or materials handling vehicle 300.

The materials handling vehicle 300 lowers the mobile storage cart 400onto the mobile storage cart transfer node 420. The transporter 500 getscloser to the materials handling vehicle 300 and rotates toward themobile storage cart transfer node 420.

The transporter 500 arrives at the mobile storage cart transfer node 420under the mobile storage cart 400 and carries the mobile storage cart400 away in a suitable direction. Examples of transporters 500 are shownand described in more detail, for example, in U.S. Patent ApplicationPublication US 2008/0166217 A1.

A warehouse management computing hub and the materials handling vehicle300 may be collectively configured to execute a place operationcomprising selection of a mobile storage cart transfer node 420 that isaccessible by a transporter 500 and the materials handling vehicle 300,and retrieval of a target mobile storage cart 400 from the mobilestorage cart transfer node 420 by engaging the target mobile storagecart 400 with a lifting mechanism of the materials handling vehicle 300.

A materials handling vehicle 300 arrives at a mobile storage carttransfer node 420. Multiple transporters 500, each carrying a mobilestorage cart 400, approach the materials handling vehicle 300, with thefirst transporter 500 assigned to the mobile storage cart transfer node420.

The first transporter 500 carries the mobile storage cart 400 to theassigned mobile storage cart transfer node 420 in front of the materialshandling vehicle 300.

The materials handling vehicle 300 moves down the aisle 220 away fromthe mobile storage cart transfer node 420. The first transporter 500travels under the first level of the lower level of rack bays 218 of themultilevel warehouse racking system 200 in a suitable direction. Moretransporters 500, each carrying a mobile storage cart 400, move in theaisle 220 in a suitable direction. In some embodiments, transporters 500follow the materials handling vehicle 300 like a train moving down theaisle 220.

Referring again to FIG. 1I, this application further includes methods ofoperating a goods storage and retrieval system 100. The method includesproviding the goods storage and retrieval system 100 and navigating thematerials handling vehicle 300 along the inventory transit surface 110to the target tote through the use of the navigation subsystem 360 andthe one or more vehicular controllers independent of movement of thetransporter 500 within the goods storage and retrieval system 100. Themethod includes engaging or disengaging the target tote with the pickingattachment secured to the fork carriage assembly 310 through use of theX-Y-Z-Ψ positioner at the tote transfer zone 219 and at multiple levelsof the multilevel warehouse racking system 200 independent of movementof the transporter 500 within the goods storage and retrieval system100.

Referring to FIGS. 1I, 1E, and 1F, the method further includes placing,with the picking attachment, the target tote on the tote transfer zone219 or on a level of the multilevel warehouse racking system 200 andengaging the target tote 214 with the transporter 500 through use of thetransporter-based engagement hardware 540 comprising a transporterlifting surface 520. Engaging the target tote 214 with the transporter500 may further include lifting the target tote 214 relative to a totesupporting surface 219A of the tote transfer zone 219 with thetransporter lifting surface 520.

Referring again to FIG. 1I, in some embodiments, the method furtherincludes transmitting, via the warehouse management computing hub,instructions to the materials handling vehicle 300 and the transporter500. The method may further comprise transporting the target tote withthe transporter 500 to a goods receiving station 610 comprising a goodsselection terminal 620 and removing the target tote from the transporterlifting surface. Removing the target tote may include elevating atransporter raising surface from an access height flush with theinventory transit surface to a selection height.

The method may further include providing a mobile storage cart 400 andengaging the mobile storage cart 400 with the fork carriage assembly 310through the use of a cart engagement subsystem of the materials handlingvehicle 300. The method then includes placing, with the pickingattachment, the target tote in the mobile storage cart 400 engaged bythe fork carriage assembly 310. In some embodiments, the method thenfurther includes disengaging the mobile storage cart 400 with the forkcarriage assembly 310 through the use of a cart engagement system of thematerials handling vehicle 300 and engaging the mobile storage cart 400with the transporter lifting surface. The method then includestransporting the mobile storage cart 400 with the transporter 500 to agoods receiving station 610 comprising a goods selection terminal 620and removing the target tote from the mobile storage cart 400.

Referring to FIGS. 11-12, this application is further directed to amaterials handling vehicle 900 comprising a vehicle body 301, aplurality of wheels 306 supporting the vehicle body 301 and defining adirection of travel 902 for the vehicle body 301, a braking system 371,a traction control unit 372, and a steering assembly 373, eachoperatively coupled to one or more of the plurality of wheels 306, amast assembly 302, a monofork carriage assembly 910 coupled to the mastassembly 302 for movement along a lifting dimension of the mast assembly302, and a transport, engagement, or disengagement accessory configuredto facilitate transport, engagement, or disengagement of materials bythe materials handling vehicle 900. The transport, engagement, ordisengagement accessories may be any of the accessories previouslydescribed, such as, but not limited to, a picking attachment 320, apicking attachment subsystem 321, cart engagement subsystem 350, anavigation subsystem 360, a scanning laser, a vision system, a 3D Timeof Flight (TOF) system, an obstacle-detecting sensor, or other automatedstorage and retrieval system hardware. Lastly, the monofork carriageassembly comprises a hollow body portion 912 accommodating at least aportion of the transport, engagement, or disengagement accessorytherein. In embodiments, the hollow body portion 912 may include thecart engagement sensors 355, as shown in FIG. 5B.

The monofork carriage assembly 910 defines an operator compartment width914 that is oriented across the direction of travel 902 of the vehiclebody, and the operator compartment width 914 may be between about 100 cmand about 125 cm. A “monofork” carriage assembly 910 can bedistinguished from conventional materials handling vehicle lifting forksbecause the monofork carriage assembly 910 comprises a unitary materialshandling platform 916 that is oriented across the direction of travel902 of the vehicle body 301 and defines a platform width 917 parallel tothe operator compartment width 914. The platform width 917 may be atleast about 75 cm and is less than the operator compartment width 914.The unitary materials handling platform 916 may comprise a leading face918 that is oriented across the direction of travel 902 of the vehiclebody 301. The leading face 918 of the platform 916 forms a protrudingarc that extends across the platform width 917 and protrudes along thedirection of travel 902 of the vehicle body 301. Furthermore, theunitary materials handling platform 916 may comprise at least twoopposing pairs of vertically oriented cart stabilizers 919. The twoopposing pairs of cart stabilizers 919 are located on opposite sides ofthe unitary materials handling platform 916 along the direction oftravel 902 of the vehicle body 301, and each cart stabilizer 919comprises an inclined contact edge facing an opposing inclined contactedge of a cart stabilizer 919 on an opposite side of the unitarymaterials handling platform 916. In this manner, the aforementioned cartstabilizers 919 will operate to automatically align a mobile storagecart or similar object that is slightly askew with respect to thematerials handling platform 916, as the materials handling platform 916and the contact edges of the cart stabilizers 919 are lifted intocontact with the mobile storage cart.

The monofork carriage assembly 910 may be removably coupled to the mastassembly 302. In addition, the unitary materials handling platform 916may engage the mobile storage cart through the use of mechanicallatches, such as, but not limited to, dowels and corresponding holes.Specifically, the unitary materials handling platform 916 may comprisedowels that deviate from the parallel plane flush with the unitarymaterials handling platform 916, and the mobile storage cart maycomprise holes corresponding to the placement of dowels on the unitarymaterials handling platform 916. These corresponding holes on the mobilestorage cart are configured to receive the dowels on the unitarymaterials handling platform 916, thereby securing the mobile storagecart in place on the unitary materials handling platform 916.

For the purposes of describing and defining the present invention it isnoted that the term “about” is utilized herein to represent the inherentdegree of uncertainty that may be attributed to any quantitativecomparison, value, measurement, or other representation. The term“about” is also utilized herein to represent the degree by which aquantitative representation may vary from a stated reference withoutresulting in a change in the basic function of the subject matter atissue.

Having described the subject matter of the present disclosure in detailand by reference to specific embodiments thereof, it is noted that thevarious details disclosed herein should not be taken to imply that thesedetails relate to elements that are essential components of the variousembodiments described herein, even in cases where a particular elementis illustrated in each of the drawings that accompany the presentdescription. Further, it will be apparent that modifications andvariations are possible without departing from the scope of the presentdisclosure, including, but not limited to, embodiments defined in theappended claims. More specifically, although some aspects of the presentdisclosure are identified herein as preferred or particularlyadvantageous, it is contemplated that the present disclosure is notnecessarily limited to these aspects.

It is noted that one or more of the following claims utilize the term“wherein” as a transitional phrase. For the purposes of defining thepresent invention, it is noted that this term is introduced in theclaims as an open-ended transitional phrase that is used to introduce arecitation of a series of characteristics of the structure and should beinterpreted in like manner as the more commonly used open-ended preambleterm “comprising.”

What is claimed is:
 1. A goods storage and retrieval system, comprisinga multilevel warehouse racking system comprising a mobile storage cart,a tote transfer zone forming a bottom level of the multilevel warehouseracking system, a materials handling vehicle comprising a mast assembly,a picking attachment, and vehicle-based cart engagement hardware, atarget tote, and a transporter comprising transporter-based engagementhardware, wherein: the transporter-based engagement hardware enables thetransporter to engage, transport, and disengage the target tote at thetote transfer zone independent of movement of the materials handlingvehicle within the goods storage and retrieval system; thetransporter-based engagement hardware enables the transporter to engage,transport, and disengage the mobile storage cart at a variety oflocations along an inventory transit surface of the goods storage andretrieval system independent of movement of the materials handlingvehicle within the goods storage and retrieval system; the pickingattachment is coupled to the mast assembly for movement along a liftingdimension of the mast assembly to (i) engage and disengage the targettote at the tote transfer zone and at multiple levels of the multilevelwarehouse racking system independent of movement of the transporterwithin the goods storage and retrieval system and (ii) transport thetarget tote to the tote transfer zone and to multiple levels of themultilevel warehouse racking system independent of movement of thetransporter within the goods storage and retrieval system; and the mastassembly and the picking attachment are configured to access multiplelevels of the multilevel warehouse racking system, the pickingattachment of the materials handling vehicle is configured to (i)transfer totes between the multilevel warehouse racking system and themobile storage cart at multiple levels of the multilevel warehouseracking system when the mobile storage cart is engaged by the materialshandling vehicle, (ii) transfer totes between the tote transfer zone andthe mobile storage cart when the mobile storage cart is engaged by thematerials handling vehicle, (iii) transfer totes between the multilevelwarehouse racking system and the transporter, and (iv) transfer totesbetween the tote transfer zone and the transporter; the vehicle-basedcart engagement hardware is coupled to the mast assembly for movementalong a lifting dimension of the mast assembly to (i) engage anddisengage the mobile storage cart at a variety of locations along theinventory transit surface of the goods storage and retrieval systemindependent of movement of the transporter within the goods storage andretrieval system and (ii) transport the mobile storage cart to multiplelevels of the multilevel warehouse racking system independent ofmovement of the transporter within the goods storage and retrievalsystem; and the mobile storage cart comprises a transporter accessopening that is sized and configured to permit the transporter to enterand exit through the transporter access opening along the inventorytransit surface.
 2. The goods storage and retrieval system of claim 1,wherein: the target tote has a tote width t; the target tote comprises apair of protruding rims positioned on opposite sides of the target tote,defining a target tote rimmed width r; the tote transfer zone comprisesa plurality of tote suspension tracks defined by a track spacing b; andt<b<r.
 3. The goods storage and retrieval system of claim 1, wherein thetote transfer zone is elevated above the inventory transit surface ofthe goods storage and retrieval system.
 4. The goods storage andretrieval system of claim 1, wherein: the multilevel warehouse rackingsystem comprises a first rack and a second rack arranged on oppositesides of a racking system aisle; the first and second racks define endpoints of the racking system aisle; and the tote transfer zone extendspast the end points of the racking system aisle.
 5. The goods storageand retrieval system of claim 1, wherein the transporter comprises atransporter lifting surface and is structurally configured to lift thetarget tote relative to a tote supporting surface of the tote transferzone by elevating the transporter lifting surface from a travelingheight to a transporting height.
 6. The goods storage and retrievalsystem of claim 5, further comprising a goods receiving stationcomprising a goods selection terminal outfitted for removal of thetarget tote from the transporter lifting surface.
 7. The goods storageand retrieval system of claim 6, wherein: the goods selection terminalcomprises an operator platform above an inventory transit surface of thegoods storage and retrieval system; and the operator platform comprisesa goods access portal that is accessible by an operator from above theoperator platform and by the transporter from below the operatorplatform.
 8. The goods storage and retrieval system of claim 7, whereinthe transporter is further configured to elevate the transporter liftingsurface to a height of the operator platform.
 9. The goods storage andretrieval system of claim 7, wherein the goods selection terminalcomprises a transporter raising surface that is flush with the inventorytransit surface, aligned with the goods access portal, and configured toelevate the transporter from the inventory transit surface of the goodsstorage and retrieval system to the operator platform.
 10. The goodsstorage and retrieval system of claim 1, wherein: the materials handlingvehicle further comprises one or more vehicular controllers; the pickingattachment comprises an X-Y-Z-Ψ positioner; and the one or morevehicular controllers executes vehicle functions to use the X-Y-Z-Ψpositioner of the picking attachment to engage and disengage the targettote positioned in the multilevel warehouse racking system with thepicking attachment.
 11. The goods storage and retrieval system of claim1, wherein: the materials handling vehicle further comprises one or morevehicular controllers; the picking attachment comprises an X-Y-Z-Ψpositioner; and the one or more vehicular controllers executes vehiclefunctions to use the X-Y-Z-Ψ positioner of the picking attachment toengage and disengage the target tote positioned on the transporter withthe picking attachment.
 12. The goods storage and retrieval system ofclaim 1, wherein: the materials handling vehicle further comprises anavigation subsystem comprising a vision system; the multilevelwarehouse racking system comprises a target fiducial associated with thetarget tote to guide engagement of the target tote with the pickingattachment; the navigation subsystem is configured to position thematerials handling vehicle such that the target fiducial is within afield of view of the vision system; the materials handling vehiclefurther comprises one or more vehicular controllers and a pickingattachment subsystem comprising the picking attachment and atime-of-flight (TOF) system; the picking attachment comprises an X-Y-Z-Ψpositioner; the picking attachment subsystem is configured to generate atarget TOF depth map of the target tote; and the one or more vehicularcontrollers of the materials handling vehicle executes vehicle functionsto use the X-Y-Z-Ψ positioner of the picking attachment subsystem toengage the target tote with the picking attachment based on the targetTOF depth map.
 13. The goods storage and retrieval system of claim 12,wherein: the materials handling vehicle further comprises a navigationsubsystem; and the navigation subsystem is configured to position thematerials handling vehicle such that the target tote is within a toteengagement field of view of the TOF system.
 14. The goods storage andretrieval system of claim 1, wherein the picking attachment comprises anX-Y-Z-Ψ positioner comprising: an X-positioner configured to move thepicking attachment in a first degree of freedom along a first lateralaxis in a lateral plane; a Y-positioner configured to move the pickingattachment in a second degree of freedom along a second lateral axisperpendicular to the first lateral axis in the lateral plane; aZ-positioner configured to move the picking attachment in a third degreeof freedom along a Z-axis perpendicular to the first lateral axis andthe second lateral axis; and a rotational Ψ-positioner configured torotate the picking attachment in a fourth degree of freedom about theZ-axis.
 15. The goods storage and retrieval system of claim 1, wherein:the materials handling vehicle further comprises a navigation subsystemcomprising a vision system; the multilevel warehouse racking systemcomprises a target fiducial associated with the target tote to guideengagement of the target tote with the picking attachment; and thenavigation subsystem is configured to position the materials handlingvehicle such that the target fiducial is within a field of view of thevision system.
 16. The goods storage and retrieval system of claim 15,wherein: the multilevel warehouse racking system comprises a pluralityof target fiducials associated with the target tote; and one of thetarget fiducials is positioned on a shelf unit of a rack module; andanother of the target fiducials is positioned on the target tote. 17.The goods storage and retrieval system of claim 1, further comprising awarehouse management computing hub in communication with the transporterand the materials handling vehicle and programmed to instruct thetransporter and the materials handling vehicle to coordinate engagement,transport, and disengagement of the target tote in the goods storage andretrieval system.
 18. The goods storage and retrieval system of claim 1,further comprising a plurality of RFID tags embedded in an inventorytransit surface of the goods storage and retrieval system at vehiclestop locations, tote transfer zones, transfer nodes, pick-placelocations, or combinations thereof.
 19. The goods storage and retrievalsystem of claim 1, wherein the vehicle-based cart engagement hardwarecomprises a mobile storage cart support platform defined by one or morevertically-oriented cart lifting forks.
 20. The goods storage andretrieval system of claim 1, wherein the vehicle-based cart engagementhardware comprises anti-rock cart engagement hardware configured toengage a top end of the mobile storage cart.
 21. The goods storage andretrieval system of claim 20, wherein the anti-rock cart engagementhardware comprises a pair of support arms configured to engage the topend of the mobile storage cart.
 22. The goods storage and retrievalsystem of claim 21, wherein the anti-rock cart engagement hardwarecomprises lateral anti-rock hardware wherein each support arm comprisesa hook subtending extension, and the mobile storage cart comprises apair of extension passages structurally configured to permit the hooksubtending extensions to pass at least partially through the pair ofextension passages.
 23. The goods storage and retrieval system of claim21, wherein the anti-rock cart engagement hardware comprises front-rearanti-rock hardware wherein each support arm comprises an anti-rock hookdefining a notch, the anti-rock hook extends downwardly at a distalportion of the support arm to define an engagement gap between a hooksubtending extension and a terminal portion of the anti-rock hook, andthe mobile storage cart comprises hook engaging features structurallyconfigured to engage the anti-rock hooks of the pair of support arms.24. The goods storage and retrieval system of claim 21, wherein: eachsupport arm comprises an anti-rock hook defining a notch, and a hooksubtending extension; and the anti-rock hook extends downwardly at adistal portion of the support arm to define an engagement gap betweenthe hook subtending extension and a terminal portion of the anti-rockhook.
 25. The goods storage and retrieval system of claim 24, whereinthe mobile storage cart comprises: hook engaging features structurallyconfigured to engage the anti-rock hooks of the pair of support arms;and a pair of extension passages structurally configured to permit thehook subtending extensions to pass at least partially through the pairof extension passages to permit the anti-rock hooks of the pair ofsupport arms to engage the hook engaging features of the mobile storagecart while the pair of support arms engage a top end of the mobilestorage cart.
 26. The goods storage and retrieval system of claim 1,wherein: the mobile storage cart comprises at least twovertically-oriented fork slots; the vehicle-based cart engagementhardware comprises a mobile storage cart support platform defined by oneor more vertically-oriented cart lifting forks; and thevertically-oriented fork slots are structurally configured to receivethe vertically-oriented cart lifting forks.
 27. The goods storage andretrieval system of claim 1, wherein: the transporter comprises atransporter lifting surface and is structurally configured to lift themobile storage cart off of the inventory transit surface upon which themultilevel warehouse racking system is supported by elevating thetransporter lifting surface from a traveling height to a transportingheight; and the mobile storage cart is structurally configured to permitthe transporter to enter and exit a lifting zone beneath the mobilestorage cart in at least two orthogonal directions, with the liftingsurface of the transporter at the traveling height.
 28. The goodsstorage and retrieval system of claim 1, wherein: the materials handlingvehicle further comprises a vehicle body, a plurality of vehicle wheelssupporting the vehicle body, a traction control unit, a braking system,and a steering assembly, each operatively coupled to one or more of thevehicle wheels, a fork carriage assembly movably coupled to the mastassembly, a mast assembly control unit, a carriage control unit, thepicking attachment secured to the fork carriage assembly, a cartengagement subsystem, a navigation subsystem, and one or more vehicularcontrollers in communication with the traction control unit, the brakingsystem, the steering assembly, the mast assembly control unit, thecarriage control unit, the picking attachment, the vehicle-based cartengagement hardware, and the navigation subsystem; the cart engagementsubsystem is characterized by a storage cart engagement field of view;and the one or more vehicular controllers of the materials handlingvehicle executes vehicle functions to (i) use the navigation subsystemto navigate the materials handling vehicle along the inventory transitsurface to a localized engagement position where a cart home position iswithin the storage cart engagement field of view, and (ii) use the cartengagement subsystem to engage the mobile storage cart in the cart homeposition with the fork carriage assembly.
 29. A method of operating agoods storage and retrieval system, the method comprising: providing thegoods storage and retrieval system comprising a multilevel warehouseracking system, a materials handling vehicle disposed on an inventorytransit surface, a tote transfer zone forming a bottom level of themultilevel warehouse racking system, a target tote, and a transportercomprising transporter-based engagement hardware wherein the materialshandling vehicle comprises a traction control unit, a braking system,and a steering assembly, each operatively coupled to one or more of thevehicle wheels, a mast assembly, a fork carriage assembly movablycoupled to the mast assembly, a mast assembly control unit, a carriagecontrol unit, a picking attachment comprising an X-Y-Z-Ψ positionersecured to the fork carriage assembly, a navigation subsystem, and oneor more vehicular controllers in communication with the traction controlunit, the braking system, the steering assembly, the mast assemblycontrol unit, the carriage control unit, the picking attachment, and thenavigation subsystem; navigating the materials handling vehicle alongthe inventory transit surface to the target tote through use of thenavigation subsystem and the one or more vehicular controllersindependent of movement of the transporter within the goods storage andretrieval system; engaging or disengaging the target tote with thepicking attachment secured to the fork carriage assembly through use ofthe X-Y-Z-Ψ positioner at the tote transfer zone and at multiple levelsof the multilevel warehouse racking system independent of movement ofthe transporter within the goods storage and retrieval system; placingwith the picking attachment the target tote on the tote transfer zone oron a level of the multilevel warehouse racking system; and engaging thetarget tote with the transporter through use of the transporter-basedengagement hardware comprising a transporter lifting surface, engagingthe target tote with the transporter further comprises lifting thetarget tote relative to a tote supporting surface of the tote transferzone with the transporter lifting surface.
 30. The method of claim 29,further comprising transmitting, via a warehouse management computinghub, instructions to the materials handling vehicle and the transporter.31. The method of claim 29, further comprising: transporting the targettote with the transporter to a goods receiving station comprising agoods selection terminal; and removing the target tote from thetransporter lifting surface.
 32. The method of claim 31, whereinremoving the target tote further comprises elevating a transporterraising surface from an access height flush with the inventory transitsurface to a selection height.
 33. The method of claim 29, furthercomprising placing with the picking attachment the target tote on alifting surface of the transporter.
 34. The method of claim 29, furthercomprising: providing a mobile storage cart; engaging the mobile storagecart with the fork carriage assembly through the use of a cartengagement subsystem of the materials handling vehicle; and placing withthe picking attachment the target tote in the mobile storage cartengaged by the fork carriage assembly.
 35. The method of claim 34,further comprising: disengaging the mobile storage cart with the forkcarriage assembly through the use of a cart engagement subsystem of thematerials handling vehicle; engaging the mobile storage cart with thetransporter lifting surface; transporting the mobile storage cart withthe transporter to a goods receiving station comprising a goodsselection terminal; and removing the target tote from the mobile storagecart.
 36. A goods storage and retrieval system, comprising a multilevelwarehouse racking system comprising a tote transfer zone, a materialshandling vehicle comprising a mast assembly and a picking attachment, atarget tote, a mobile storage cart, and a transporter comprisingtransporter-based engagement hardware, wherein: the transporter-basedengagement hardware enables the transporter to engage, transport, anddisengage the target tote at the tote transfer zone independent ofmovement of the materials handling vehicle within the goods storage andretrieval system; the picking attachment is coupled to the mast assemblyfor movement along a lifting dimension of the mast assembly to (i)engage and disengage the target tote at the tote transfer zone and atmultiple levels of the multilevel warehouse racking system independentof movement of the transporter within the goods storage and retrievalsystem and (ii) transport the target tote to the tote transfer zone andto multiple levels of the multilevel warehouse racking systemindependent of movement of the transporter within the goods storage andretrieval system; the mast assembly and the picking attachment areconfigured to access multiple levels of the multilevel warehouse rackingsystem; the mobile storage cart comprises a transporter access openingthat is sized and configured to permit the transporter to enter and exitthrough the transporter access opening along an inventory transitsurface of the goods storage and retrieval system; the transporter-basedengagement hardware enables the transporter to engage, transport, anddisengage the mobile storage cart at a variety of locations along theinventory transit surface of the goods storage and retrieval systemindependent of movement of the materials handling vehicle within thegoods storage and retrieval system; the materials handling vehiclefurther comprises vehicle-based cart engagement hardware that is coupledto the mast assembly for movement along a lifting dimension of the mastassembly to (i) engage and disengage the mobile storage cart at avariety of locations along an inventory transit surface of the goodsstorage and retrieval system independent of movement of the transporterwithin the goods storage and retrieval system and (ii) transport themobile storage cart to multiple levels of the multilevel warehouseracking system independent of movement of the transporter within thegoods storage and retrieval system; and the picking attachment of thematerials handling vehicle is configured to (i) transfer totes betweenthe multilevel warehouse racking system and the mobile storage cart atmultiple levels of the multilevel warehouse racking system when themobile storage cart is engaged by the materials handling vehicle, (ii)transfer totes between the tote transfer zone and the mobile storagecart when the mobile storage cart is engaged by the materials handlingvehicle, (iii) transfer totes between the multilevel warehouse rackingsystem and the transporter, and (iv) transfer totes between the totetransfer zone and the transporter.
 37. A method of operating a goodsstorage and retrieval system, the method comprising: providing the goodsstorage and retrieval system comprising a multilevel warehouse rackingsystem, a materials handling vehicle disposed on an inventory transitsurface, a tote transfer zone forming a bottom level of the multilevelwarehouse racking system, a target tote, and a transporter comprisingtransporter-based engagement hardware wherein the materials handlingvehicle comprises a traction control unit, a braking system, and asteering assembly, each operatively coupled to one or more of thevehicle wheels, a mast assembly, a fork carriage assembly movablycoupled to the mast assembly, a mast assembly control unit, a carriagecontrol unit, a picking attachment comprising an X-Y-Z-Ψ positionersecured to the fork carriage assembly, a navigation subsystem, and oneor more vehicular controllers in communication with the traction controlunit, the braking system, the steering assembly, the mast assemblycontrol unit, the carriage control unit, the picking attachment, and thenavigation subsystem; navigating the materials handling vehicle alongthe inventory transit surface to the target tote through use of thenavigation subsystem and the one or more vehicular controllersindependent of movement of the transporter within the goods storage andretrieval system; engaging or disengaging the target tote with thepicking attachment secured to the fork carriage assembly through use ofthe X-Y-Z-Ψ positioner at the tote transfer zone and at multiple levelsof the multilevel warehouse racking system independent of movement ofthe transporter within the goods storage and retrieval system; placingwith the picking attachment the target tote on the tote transfer zone oron a level of the multilevel warehouse racking system; engaging thetarget tote with the transporter through use of the transporter-basedengagement hardware comprising a transporter lifting surface;transporting the target tote with the transporter to a goods receivingstation comprising a goods selection terminal; and removing the targettote from the transporter lifting surface, removing the target totefurther comprises elevating a transporter raising surface from an accessheight flush with the inventory transit surface to a selection height.